Iguala (Mexico) (AFP) - At least 21 bodies were pulled from a mass grave in southern Mexico and authorities checked Sunday if they were among a group of 43 students missing since a police shooting last week.
Guerrero state Health Secretary Lazaron Mazon told AFP "some charred" remains were among the bodies found on a hill outside the town of Iguala, where the students were last seen.
He said 21 bodies have been exhumed since the unmarked grave was found Saturday in the Pueblo Viejo hamlet, 200 kilometers (125 miles) south of Mexico City, and that they have to be identified through DNA analysis.
Authorities had until now withheld the number of bodies found at the remote site, which was cordoned off and guarded by scores of troops and police.
Vidulfo Rosales, a lawyer for the families, said 35 relatives have given DNA samples so far.
As relatives nervously waited for news, hundreds of fellow students from the missing group's teacher training college blocked the highway between Guerrero's capital Chilpancingo and Acapulco, voicing anger at the authorities.
If the bodies are confirmed to be those of the students, it would be one of the worst slaughters that Mexico has witnessed since the drug war intensified in 2006, leaving 80,000 people dead to date.
The grim find came a week after the students disappeared when gang-linked municipal police shot at buses they had seized to return home from Iguala, where survivors say they had conducted fundraising activities.
In all, three students were killed in the shooting and another three people died when suspected gang members shot at a football team's bus outside Iguala later that night.
Witnesses say several students, who are from a teacher training college known as a hotbed of radical protests, were whisked away in police vehicles.
- 'Land of the wicked' -
Inaky Blanco, Guerrero's chief prosecutor, said members of Iguala's police force are part of a gang known as Guerreros Unidos, which is suspected of taking part in last week's violence.
The graves were found after some of the 30 suspects detained in the case told authorities about their location, Blanco said. The detainees include 22 police officers.
An arrest warrant has been issued for the mayor, who has fled.
In Pueblo Viejo, a hamlet surrounded by forests and mountains, a resident said the region is dominated by a drug gang and that he had seen municipal police officers going up the hill in recent days, before authorities discovered the mass grave.
"They were going up there back and forth," said the resident, Jose Garcia, pointing to a location between two mountains where the graves were found.
Juan Lopez Villanueva, an official from the National Human Rights Commission, said that six pits were found up a steep hill probably inaccessible by car.
- Angry relatives -
Outside Chilpancingo, hundreds of students blocked the highway to Acapulco, holding signs reading "Fraudulent government that kills students."
Some parents who participated in the protest lashed out at Governor Angel Aguirre, promising "war" against the state leader, who appealed for calm after the grave was discovered.
They said they were shown pictures of bodies, but that they did not resemble their missing children.
"As parents, we reject this situation. It's not the youngsters. We know they're holding them alive," said Manuel Martinez, whose son is among the missing.
But police links to organized crime have raised fears about the fate of the students, in a country where drug cartels regularly hide bodies in mass graves.
Around 30 bodies were found this year in mass graves in Iguala.
"This is the land of the wicked," said Garcia, the Pueblo Viejo resident.